I recently bought a used car. There is a large stain on the carpet in the boot from which emits a very unpleasant whiff. I don't get it in the car but everytime I open the boot, it wafts out. I'm not sure what was spilled there. I don't think it's blood :-) . Part of the stain is on the panel covering the spare wheel which can be lifted out of the car. The remainder is on the carpet beside this panel.
What is the best way to get rid of smell?